Camellia has lost most of it’s leaves

[BorgQueen]

Do they come back ?

It’s 4 years old, white flowering , it lost a lot of buds to the frost in March, barely any flowers and has been shedding leaves ever since, the few remaining are quite yellow.
I also have a deep pink one that’s a year younger, it flowered magnificently this year and has glossy dark leaves and plenty of new growth.
I repotted both last year with new ericaceous compost, they are in the same sized pots in the same location.

I hope someone with a bit more knowledge comes along, but I would try to check the roots, if they're still healthy then there's hope.

Possibly vine weevils if it's in a pot, I'd change the compost and treat with nematode.